pub fn new_birthday_probability(n: u32) -> f64 {
    let mut all_different_prob = 1.0;
    for i in 1..n {
        all_different_prob *= (365 - i) as f64 / 365.0;
    }
    let probability =  1.0 - all_different_prob;
    (probability * 10000f64).round() / 10000f64
}